Researchers from ETH Zurich have developed a new type of tissue-engineered cardiac patch that promises to seal and heal defective areas of the heart.

The team developed a 3D-printed heart patch for intraventricular implantation to serve as an alternative to the bovine pericardial patches (BPPs) currently in use but that have significant disadvantages. Specifically, BPPs cannot be broken down and they can also cause unwanted reactions like calcification, thrombosis or inflammation.

Three perspectives of a support scaffold model (top) and printed (bottom). Source: Soft Robotics Lab/ETH Zurich

"Traditional heart patches do not integrate into the heart tissue and remain permanently in the body. We wanted to solve this problem with our patch, which integrates into the existing heart tissue," explained the researchers.

The team believes that the "RCPatch" (Reinforced Cardiac Patch) could potentially become an alternative to BPPs patches. The RCPatch, consists of three parts: a delicate mesh that seals the damage, a 3D-printed scaffold for stability and a hydrogel filled with heart muscle cells. The scaffold features a lattice structure made up of a degradable 3D-printed polymer. "The scaffold is stable enough and can be filled with a hydrogel containing living cells," explained the researchers.

The lattice structure’s thin mesh ensures that it could be easily attached to the heart. The team then enriched the mesh with the same hydrogel, thus allowing the RCPatch to integrate into the surrounding tissue and grow together with the heart muscle cells.

"The big advantage is that the scaffold is completely degraded after the cells have combined with the tissue. This means that no foreign body remains," the researchers noted.

In the lab, the team successfully implanted the patch and it withstood the high pressure in the heart. Further, the patch prevented bleeding and restored cardiac function.

An article detailing the patch, “Volumetric 3D Printing and Melt‐Electrowriting to Fabricate Implantable Reinforced Cardiac Tissue Patches,” appears in the journal Advanced Materials.